Optoelectronic memristors are new multifunctional devices
with
both electrically tunable and light-tunable synaptic plasticity, attracting
great attention as key promising devices for optoelectronic neuromorphic
computing systems. At present, the conductance modulation in most
optoelectronic memristors is conducted in a hybrid photoelectric mode,
suffering some problems such as heat generation and control complexity.
Here, an optoelectronic memristor based on the p+-Si/n-ZnO
heterojunction is proposed where the conductance can be reversibly
modulated in an all-optically controlled mode. The electron detrapping/trapping
mechanism at the p+-Si/n-ZnO interface barrier region is
presented to explain the light-induced conductance potentiation/depression
behavior. Furthermore, some synaptic functions, including excitatory
postsynaptic current (EPSC), inhibitory postsynaptic current (IPSC),
and paired-pulse facilitation (PPF), are successfully mimicked in
the p+-Si/n-ZnO heterojunction memristor, instructing its
application potential for optoelectronic neuromorphic computing.